This invention relates to a package case, particularly to one having four circumferential walls of special structure producing shock-absorbing function, and permitting the package case possess excellent buffering and shock-absorbing effect.
Package cases generally have material and structure for different products, from simple things to sophisticated electronic appliances. As for computers and related appliances, Styrofoam package cases are used for packing them with their thick walls, protecting them from shocks during transporting, and sometimes air bubble bags are used for small products instead of Styrofoam. However, Styrofoam package cases have to be made by means of accurate and complete molds owing to special features of Styrofoam, and may produce toxic gas and odor in manufacturing process, presenting potential danger to people and animals in a factory and its neighborhood. Light Styrofoam package cases generally have large dimensions, impossible to fold or insert in each other, resulting in high charge for transporting and storage, unprofitable for makers.
In addition, Styrofoam has inferior expansibility to produce easily rupture or rip off, lowering its protective effect, and if worse, losing protective function. When consumers buy a product contained in a Styrofoam package case, the Styrofoam package case becomes useless after the product is taken off, uneasy to treat or discard owing to its largeness. When it is discarded, it may produce toxic gas and odor in case of burning, making up a second public harm to the environment. As for air bubble bags, though they have good shock-absorbing effect, air bubbles may be punctured during transporting by exterior force, losing shock-absorbing function of the flattened portion, forming risk to the product therein in the remaining course of transporting. Provided air bubble bags should receive one time of large shock to damage a large portion of air bubbles, they may give rise to a large vibration to the product packaged therein to be damaged more or less.
So, a Patent application with filing number Ser. No. 09/342,199 was filed on Jun. 29, 1999 for a package case, in order to improve disadvantages of conventional package cases, as shown in FIG. 53.